Panel finds high levels of arsenic in drinking water

March 24, 1999
Web posted at: 1:49 PM EST (1849 GMT)

WASHINGTON (AP) -- High levels of arsenic are being allowed in drinking water, despite findings that the government-sanctioned standards pose an unacceptable risk of cancer, an advisory panel to the federal government has concluded.

The study by a committee of the National Academy of Sciences was embraced by environmentalists and water quality experts as a clarion call for the Environmental Protection Agency to strengthen its regulations on allowable arsenic levels in tap water.

The report, made public Tuesday, concluded that the EPA's standard of a maximum 50 micrograms of arsenic per liter of water "does not sufficiently protect public health" and should be lowered "as promptly as possible."

The EPA, which has missed three deadlines on dealing with the arsenic regulations, agreed with the report's findings, and officials said a new arsenic standard for drinking water would be proposed by next January. A final standard, however, is not likely to be in place before late 2000.

"We agree with the conclusions of the report that we need to strengthen our drinking water standards to protect public health and the environment," said Charles Fox, assistant EPA administrator for water issues.

It was unclear how many people drink water with high levels of arsenic.

Fox said the number of water systems with arsenic levels approaching 50 micrograms per liter are relatively few, "affecting less than half of a percent of the U.S. population," and usually those that rely on groundwater. Most major metropolitan water systems get water from lakes and streams where arsenic is less of a concern.

But the American Water Works Association, which represents private experts on drinking water quality, estimated 2,200 of the 56,000 U.S. water supply systems would be affected if the EPA lowered its standard from 50 micrograms per liter to 10 micrograms. It said the cost could be $1 billion for such a reduction.

The international standard for arsenic in tap water is 10 micrograms per liter, five times tougher than the U.S. requirement, which dates back to 1942 and has not been changed despite a 1974 directive from Congress to strengthen the standard.

The special committee of the Academy's National Research Council said EPA's current maximum allowable arsenic content poses a much greater cancer risk than the agency normally considers acceptable.

Males who daily drank water at or near the maximum allowable arsenic levels had a 1 in 1,000 risk of developing bladder cancer, the study said. It cited a possibility, disputed by some panel members, of a combined cancer risk of as high as 1 in 100 over a lifetime, for those regularly exposed to the upper threshold of the EPA standard.

This far exceeds the EPA's general goal of limiting cancer risks to 1 in 10,000 over a lifetime, the scientific panel said.

Inorganic arsenic, the form most likely to cause cancer, occurs naturally in the earth and is released into groundwater that travels through rocks and soil. The highest exposure to arsenic is in drinking water from wells as opposed to areas, including most urban areas, that get drinking water from lakes and streams, officials said.

Fox said he couldn't give any estimate on what level the EPA was considering for the regulations expected to be proposed at the end of the year. But some environmentalists questioned whether the EPA's changes will be tough enough and suggested the agency may be minimizing the health impact.

The National Academy of Sciences is an independent organization chartered by Congress to advise the government.

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